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  1. #1

    Join Date
    Feb 2005
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    Eastern Canada
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    Sally Ann find.(Thrift store)

    Good Day,
    I just picked up the oddest lens I,ve ever handled.Its a Vivitar,Series One, 200mm, 3.5, Auto Focus Telephoto.Its ODD because of the built in focusing motor.
    The lens was in horrid shape.Battery compartment full of crud (cured with white vinegar) and although the glass was filthy the front element was protected by a 62mm UV filter.Lots of internal fungus(cleaned up using a 50/50 mixture of ammonia/peroxide.
    I can,t find a bloody thing on the net! Believe I saw an add from the mid !980,s featuring a similar configuration by Tamron.Can anyone help with a bit of info.on this beast? It weighs a ton,but heck,for $2.00 ya can,t go wrong.
    Cheers,
    Mike

  2. #2
    Seele's Avatar
    Join Date
    Feb 2004
    Location
    Sydney Australia
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    194
    Nothing odd about this lens, in fact I bought one new at a shop some years ago and worked it very hard too, and when it was introduced it was hailed as a trailblazer as yet criticized for its inherent shortcomings.

    It was made during the earliest days of 35mm reflex camera autofocus technology; Pentax ME-F and Canon T80 both showed some limited autofocus capabilities, but Vivitar wanted to have a lens which could fit standard manyal focus cameras btu offering autoficus function: the only way was to have it built into the lens itself as a completely self-contained unit.

    Optically, it was an Opcon-designed 200/3.3, with internal focus, a beam-splitter prism inside bleeds off a fixed percentage of light so that it functions like a 200/3.5. Extra optics under the beam splitter provides the Honeywell constrast detection sensor with a surrogate film plane, and a small motor was used to drive the focussing element.

    Even with the presence of the beam-splitter prism, I found the imaging quality excellent; after all it's a real Series 1 (Opcon designed). I can hardly say that the autofocus feature was gimmicky, but like such early experiments, its operation is nowhere near that in modern autofocus reflex cameras, mainly due to sensor technology.

    Nevertheless, several lens-integral autofocus lenses followed: Tamron made a zoom, Cosina and Sigma also made a few as well.

  3. #3

    Join Date
    Feb 2005
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    Eastern Canada
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    Thanks Seele,
    Just can,t stand the thought of having a piece of gear that I know nothing about.
    Cheers,
    Mike



 

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